William gates



. GATES.- EXTENSION ATTACHMENT FOR LADDERS. No. 515,582.

(No Model.)

Patented Feb. 27, 1894.

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I UNITED STATES PATENT t me.

WILLIAM GATES, OF NEW HAVEN, CONNECTICUT, ASSIGNOR OF ONE-HALF TO ADELBERT WV. FLINT, OF SAME PLACE.

EXTENSION ATTACHMENT FOR LADDERS.

SPECIFICATION formingpart of Letters Patent No. 515,582, dated February 27, 1894.

Application filed July 24, 1893. Serial 170481353. (No model.)

T at whom it may concern:

Be it known that I, WILLIAM GATES, of New Haven, in the county of New Haven and State of Connecticut, have invented a new Improve ment in Extension Attachments for Ladders; and I do hereby declare the following, when taken in connection with accompanying drawings and the letters and figures of reference elevation and partly in section on the line,

a-b of Fig. 1, showing the projected or normal position of the hook of the attachment by full lines and the retired or retracted position of the hook by two sets of broken lines, which indicate two different elevations of the slidingnpper ladder; Fig. 3, an enlarged view partly in section of one of the attachments with. its cover removed, and Fig. 4, a similar view looking at the open edge of the attachment.

My invention relates to an improvement in extension attachments for ladders, or in other words, to those devices employed in connection with two ladders to permit the upper ladder to be moved up and down with respect to the lower ladder, and firmly fastened thereto in any desired position. These dovices are attached to the upper ladder and provided with swinging hooks adapted to be engaged with the rungs of the lower ladder, and the object of my present invention is to produce an attachment of simple, compact, durable and effective construction, in which the projection of the hook shall be positively eft'ected by means of a trip.

With these ends in view, my invention consists in an extension attachment having certain details of construction and combinations of parts as will be hereinafter described and pointed out in the claims. I

It will be understood that two attachments are always employed with a pair of ladders, but inasmuch as the attachments will be exactly alike in construction, the illustration and description of one attachment will sutfice for an understanding of my invention. I have, however, shown in Fig. 1 of the drawings, two ladders, provided with a pair of my attachments, the upper ladder A being narrower than the lower ladder B, and arranged to slide up and down within the side pieces thereof. The lower ladder is furnished with two pairs B B, B B of guides, which embrace the sides of the upper ladder, and guide the same as it is adjusted up and down.

My improved attachment consists essentiallyof a hook C and a trip D, hung on the same pivot E, within the body F of a case having a removable cover G, the said body and cover being provided at their ends with perforated lu gs F, and G, which receive bolts having the double function of securing the cover to the body and both to the ladder. The particular construction of the body and cover, however, maybe varied as desired. The hook O is constructed at its upper end, which constitutes the real hook and is adapted tobe engaged with the rungs of the ladder, with an inclined operating face 0', the function of which will be set forth later on. At its lower end the hook is enlarged in its plane, and constructed with a longitudinal slot 0*, extending transversely through it, and receiving the flattened 8o centrally perforated head D, formed at the inner end of the trip D; the hook and trip being thus adapted to be hung on the same pivot E. As herein shown the hook is also constructed with a stop-arm G extending in 8 5 line with it below its enlarged portion, and arranged to engage with a stop H, consisting of a block, and located within the lower end of the case, as seen in Fig. 3. The function of the said stop-arm as thus constructed, is go to limit the projection of the upper end of the hook from the 1 case, as clearly shown in the said figure. If desired, however, I may dispense with the said arm and employ other means for limiting the projection of the hook. 5 I shall, however, construct the hook at its lower end so as to adapt it to be positively engaged by the trip at a point below the pivot E for the positive projection of the hook.

This engagement of the trip with the hook takes place when the trip is at the limit of its downward movement, the extreme inner end of the'trip then engaging with the ex:

7 treme inner end of the outer face of thestop-'- arm (3 The hook is further constructed at its lower end'with an inwardly projeetinglug having'two corresponding oppositely inclined cam faces and Q-which, are alter- 'nat elyengaged by a stifi spring Lseoured to the may of the case. When the hook is turnedon thepivotahhsoas to e'ngagethe jectedpositiomasshown by full line's'in'the samefigures. I

:Asherein shown I have provideda spring J, for the trip D,tl1e said spring bcingse (aired tot-he inner face of stop-arm C and extending upward intothe longitudinal slot 0. formedin the enlargedlower portion-of I the hook, and arranged to r co-operate with a long s'egtnentai recesstd, formed in. the fiat .tened head D. of the trip, and also withjxa: notch eldermdadjacent to one end of the said 1 segmental.-recess.-- "The said spring J may, ihowever, be dispensed with, as it is. not necessary to the operation of my improved (isvice; When employed it serves to prevent theunduly free vibration'ofthe pivotal trip trip swings practically unrestrained hyrthe *spring,'between the point czof the hookand. the intermediate-position in which the trip I is shown by the broken lines c in Fig. 3; Be tweens'uch intermediate position of the trip,

and its operating position in which it en D. Within the limits :of therecess'd, the

gages positively with the upper end of the stop-arm, the spring restrains the movement of the trip, and in its operating position onters the notch d so as to hold the trip in that position against accidental dislodgment. It will be seen that the trip is not free to vibrats between its intermediate and operating position,- whereby it is prevented from possiblyswinging into position to engage endwise with the rungs of the lower ladder, while the upper ladder is being lowered, but as I said before, my device is fully operative without this trip spring, and I may dispense with it.

Having now described the construction of my improved extension attachment, I will proceed to set forth the mode of its operation, using for convenience of illustration, Fig. 2 of the drawings.

Let it be supposed, for instance,- that the hook is projected and engaged with the rung 2 of the ladder, whereby the upper ladder is firmly secured, so far as downward movement is concerned, to the lower ladder. If now it is desired to lower the upper ladder for a distance represented by one rung, the upper ladder will first be lifted, against which movement there is no obstruction, through a distance somewhat exceeding the distance between the said rung 2 and the rung 3 next above it. 1a liftingthe upper-ladder as de:

scribed, the inolinedo'perating face (Yet the hook is engaged with'the. lower faoebf the,

said rung 3,wherehytheforoe ofthespring lug ofthe hook. The book having beenrebelow the rnng2. While the; attachment is l is overcome, and the h'ookthrown backlinto its retracted or retired positiomas shown by a the upper setof broken lines in thesaid figure, I the spring passing from the cam-surface c to. the camsurfaoec of the rearwardlyprojecting v .traoted as described, the npperrladder is low- I ered so as to permit the: attachment to pass8 beingthns lowered, the pivotal trip, whiohis 7 now projected, will engage with the rung 2, and be. swung around by the sameginto: the elevated positiominwhich. it 'is shown by 1 broken lines in Fig. 3, and in which its end engages 'with lthe extreineend c st the hook. In" this positionof retirement, so to speakfihe I 7 mp clears tlic rung Zidthe downward; more: I ment of the ladder and attachment. Just as,

soon, however, as the tripnpass'es ,-below the run 2,-it will fall: by gravity into its,inter;- 'mediateposition, su' pposing the deviceto be provided 'witli'a tripspring, m'intn its lowest I position supposing thedeviceisnot provided with suchaspring, :The lowering of the upperladder is continued nntilthe attachment has 1 passed belowrthe range, which, will; engage with the trip, and again throwthe samemw its elevated :;or retired position, in whieh; it

will clearrthe said rnng handfrom which it *will fall down gravity again as. soo'nas "it passe; below the said :rnfng into tho posiw I tion-in which the attachmentisshownby the 1 The upa lower set of broken lines in Fig. 2. perladderis now lifted, whereby the trip will be engaged with the lower face of the rungs. If the trip is at this time in its intermediate position, it will be at once depressed into its operating position, in which it is positively engaged with the hook, which, when the upper ladder is lifted a little farther, will be positively projectedfrom the case at a point above the rung 4:. The upper ladder is now let down a little so as to permit the hook to engage with the rung 4 in the same manner as that in which it is shown by full lines to be engaged with the rung 2. If the trip isin its operative position when the lifting of the ladder is begun, it will at once positively project thehookwithouttheslight movementrequired to move the trip from its intermediate to its operating position. The process of disconmeeting the hook from therung 2, and re-em gaging it with another rung above the same, is the same as that just described, except the final movement of the ladder is upward instead of downward.

What I wish particularly to call attention to is that the projection of the hook is positive and not dependent upon the action of any springs.

My device is composed of few parts, is not liable to derangement, and will be found to be very elfective in use.

no i I am aware thatit is not new to employ, in such devices, hooks having inclined faces for positively retracting them, nor new to coinbme trips and springs with such hooks, andI do not claim any of those constructions broadly. I would have it understood, however, that I do not limit myself to the exact construction herein shown and described, for it is apparent that some changes of form and arrangementmay be made without departing from my particular invention.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, isp 1. In an extension attachment for ladders, the combination with a case, of a hook pivotally hung within the case, and constructed at itshooked upper end with an inclined op erating face, a pivotal trip arranged to engage with the hook below thepivotthereof to positively project its upper end from the case and a spring located within the case and engagingrthe hook,'which it holds inits projected and. retracted positions, substantially as described.

2. In anextension attachment for ladders, the combination with a case, of a hook pivotally hung within the case, and constructed at its hooked upper end with an inclined operating face, a pivotal trip having the same pivotal center as the hook, and constructed to positively engage with the same below the the combination with the case thereof, of a hook :pivotally hung withinthe case and constructed at its hooked upper end with an inclined operating face, and. at its lower end with an inwardly projecting lug having two oppositely inclined cam-faces, a pivotal tri having the same pivotal center as the hook with which it positively engages below the pivotal points thereof for positively projecting the hook into its operating position, and a spring arranged to engage with the respective faces of the said lug, for holding the hook in its projected and retracted positions, substantially as described.

4:. In an extension attachment for ladders,

for holding the hook in its projected and retraoted positions, substantially as described.

5. In an extension attachment for ladders, the combination with the case thereof, of a hook pivotally hung therein,a spring secured to the case and engaging with the hook for holding the same in its projected and retracted positions, a trip pivoted on the same center as the hook and arranged to engage with the same for positively projecting itinto its operating position, and a trip spring for controlling the vibration of the pivotal trip, substantially as described.

In testimony whereof I have signed this specification in the presence of two subscribin g witnesses.

WILLIAM GATES.

.Witnesses:

ADELBERT W. FLINT, GEO. D. SEYMOUR. 

